Surface micromachined piezoelectric resonant beam filters

Piezoelectric actuation and sensing of suspended single-beam microelectrome chanical system (MEMS) resonant filters is demonstrated. Resonant frequenci es between 171 kHz and 9.2 MHz were observed for resonators with dimensions of 6-20 mum wide and 25-400 mum long. Operation was demonstrated from a va cuum pressure of 20 mTorr to atmospheric with drive voltages as low as 2.5 mV and a dynamic range of greater than 40 dB. Loaded quality factors (Q(s)) greater than 1000 resulted at 9.2 MHz and a 20 mTorr pressure. A 20 kHz tu ning range resulting from the piezoelectric poling conditions and a 75 ppm/ K frequency temperature dependency was observed. The resonators utilize a c lamped-clamped beam design with sol-gel lead zirconate titanate (PZT) as th e piezoelectric actuator and sensor, PECVD silicon dioxide as the resonant beam structure, and platinum as the top and bottom electrode. The effects o f operating temperature, operating pressure, poling condition, and drive vo ltage are reported. (C) 2001 Elsevier Science B.V. All rights reserved.